diff --git a/index.test-d.ts b/index.test-d.ts
index 3a54965..2d92542 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -16,6 +16,9 @@ pTimeout(delayedPromise(), {milliseconds: 50}).then(value => {
 pTimeout(delayedPromise(), {milliseconds: 50, message: 'error'}).then(value => {
 	expectType<string>(value);
 });
+pTimeout(delayedPromise(), {milliseconds: 50, message: false}).then(value => {
+	expectType<string>(value);
+});
 pTimeout(delayedPromise(), {milliseconds: 50, message: new Error('error')}).then(value => {
 	expectType<string>(value);
 });